diff --git a/bindings/matrix-sdk-ffi/src/authentication_service.rs b/bindings/matrix-sdk-ffi/src/authentication_service.rs
index b8d39bc63..79650704d 100644
--- a/bindings/matrix-sdk-ffi/src/authentication_service.rs
+++ b/bindings/matrix-sdk-ffi/src/authentication_service.rs
@@ -17,7 +17,6 @@ pub struct AuthenticationService {
     passphrase: Option<String>,
     client: RwLock<Option<Arc<Client>>>,
     homeserver_details: RwLock<Option<Arc<HomeserverLoginDetails>>>,
-    custom_sliding_sync_proxy: RwLock<Option<String>>,
 }
 
 impl Drop for AuthenticationService {
@@ -83,17 +82,12 @@ impl HomeserverLoginDetails {
 impl AuthenticationService {
     /// Creates a new service to authenticate a user with.
     #[uniffi::constructor]
-    pub fn new(
-        base_path: String,
-        passphrase: Option<String>,
-        custom_sliding_sync_proxy: Option<String>,
-    ) -> Arc<Self> {
+    pub fn new(base_path: String, passphrase: Option<String>) -> Arc<Self> {
         Arc::new(AuthenticationService {
             base_path,
             passphrase,
             client: RwLock::new(None),
             homeserver_details: RwLock::new(None),
-            custom_sliding_sync_proxy: RwLock::new(custom_sliding_sync_proxy),
         })
     }
 
@@ -142,9 +136,7 @@ impl AuthenticationService {
 
         // Now we've verified that it's a valid homeserver, make sure
         // there's a sliding sync proxy available one way or another.
-        if self.custom_sliding_sync_proxy.read().unwrap().is_none()
-            && client.discovered_sliding_sync_proxy().is_none()
-        {
+        if client.discovered_sliding_sync_proxy().is_none() {
             return Err(AuthenticationError::SlidingSyncNotAvailable);
         }
 
@@ -177,20 +169,10 @@ impl AuthenticationService {
         let homeserver_url = client.homeserver();
         let session = client.inner.session().ok_or(AuthenticationError::SessionMissing)?;
 
-        let sliding_sync_proxy: Option<String>;
-        if let Some(custom_proxy) = self.custom_sliding_sync_proxy.read().unwrap().clone() {
-            sliding_sync_proxy = Some(custom_proxy);
-        } else if let Some(discovered_proxy) = client.discovered_sliding_sync_proxy() {
-            sliding_sync_proxy = Some(discovered_proxy);
-        } else {
-            sliding_sync_proxy = None;
-        }
-
         let client = ClientBuilder::new()
             .base_path(self.base_path.clone())
             .passphrase(self.passphrase.clone())
             .homeserver_url(homeserver_url)
-            .sliding_sync_proxy(sliding_sync_proxy)
             .username(whoami.user_id.to_string())
             .build_inner()?;
 
diff --git a/bindings/matrix-sdk-ffi/src/client.rs b/bindings/matrix-sdk-ffi/src/client.rs
index 96964c131..0e0880ffe 100644
--- a/bindings/matrix-sdk-ffi/src/client.rs
+++ b/bindings/matrix-sdk-ffi/src/client.rs
@@ -112,10 +112,6 @@ pub struct Client {
     notification_delegate: Arc<RwLock<Option<Box<dyn NotificationDelegate>>>>,
     session_verification_controller:
         Arc<tokio::sync::RwLock<Option<SessionVerificationController>>>,
-    /// The sliding sync proxy that the client is configured to use by default.
-    /// If this value is `Some`, it will be automatically added to the builder
-    /// when calling `sliding_sync()`.
-    pub(crate) sliding_sync_proxy: Arc<RwLock<Option<String>>>,
     pub(crate) sliding_sync_reset_broadcast_tx: Arc<SharedObservable<()>>,
 }
 
@@ -142,7 +138,6 @@ impl Client {
             delegate: Arc::new(RwLock::new(None)),
             notification_delegate: Arc::new(RwLock::new(None)),
             session_verification_controller,
-            sliding_sync_proxy: Arc::new(RwLock::new(None)),
             sliding_sync_reset_broadcast_tx: Default::default(),
         };
 
@@ -217,16 +212,8 @@ impl Client {
 
     /// Restores the client from a `Session`.
     pub fn restore_session(&self, session: Session) -> Result<(), ClientError> {
-        let Session {
-            access_token,
-            refresh_token,
-            user_id,
-            device_id,
-            homeserver_url: _,
-            sliding_sync_proxy,
-        } = session;
-
-        *self.sliding_sync_proxy.write().unwrap() = sliding_sync_proxy;
+        let Session { access_token, refresh_token, user_id, device_id, homeserver_url: _ } =
+            session;
 
         let session = matrix_sdk::Session {
             access_token,
@@ -265,10 +252,6 @@ impl Client {
         })
     }
 
-    pub(crate) fn set_sliding_sync_proxy(&self, sliding_sync_proxy: Option<String>) {
-        *self.sliding_sync_proxy.write().unwrap() = sliding_sync_proxy;
-    }
-
     /// Whether or not the client's homeserver supports the password login flow.
     pub(crate) async fn supports_password_login(&self) -> anyhow::Result<bool> {
         let login_types = self.inner.get_login_types().await?;
@@ -297,7 +280,6 @@ impl Client {
             let matrix_sdk::Session { access_token, refresh_token, user_id, device_id } =
                 self.inner.session().context("Missing session")?;
             let homeserver_url = self.inner.homeserver().await.into();
-            let sliding_sync_proxy = self.sliding_sync_proxy.read().unwrap().clone();
 
             Ok(Session {
                 access_token,
@@ -305,7 +287,6 @@ impl Client {
                 user_id: user_id.to_string(),
                 device_id: device_id.to_string(),
                 homeserver_url,
-                sliding_sync_proxy,
             })
         })
     }
@@ -763,7 +744,6 @@ pub struct Session {
 
     // FFI-only fields (for now)
     pub homeserver_url: String,
-    pub sliding_sync_proxy: Option<String>,
 }
 
 #[uniffi::export]
diff --git a/bindings/matrix-sdk-ffi/src/client_builder.rs b/bindings/matrix-sdk-ffi/src/client_builder.rs
index 0b2077c7d..bcaccba9f 100644
--- a/bindings/matrix-sdk-ffi/src/client_builder.rs
+++ b/bindings/matrix-sdk-ffi/src/client_builder.rs
@@ -23,7 +23,6 @@ pub struct ClientBuilder {
     server_versions: Option<Vec<String>>,
     passphrase: Zeroizing<Option<String>>,
     user_agent: Option<String>,
-    sliding_sync_proxy: Option<String>,
     inner: MatrixClientBuilder,
 }
 
@@ -76,12 +75,6 @@ impl ClientBuilder {
         Arc::new(builder)
     }
 
-    pub fn sliding_sync_proxy(self: Arc<Self>, sliding_sync_proxy: Option<String>) -> Arc<Self> {
-        let mut builder = unwrap_or_clone_arc(self);
-        builder.sliding_sync_proxy = sliding_sync_proxy;
-        Arc::new(builder)
-    }
-
     pub fn build(self: Arc<Self>) -> Result<Arc<Client>, ClientError> {
         Ok(self.build_inner()?)
     }
@@ -128,12 +121,7 @@ impl ClientBuilder {
             );
         }
 
-        RUNTIME.block_on(async move {
-            let client = inner_builder.build().await?;
-            let c = Client::new(client);
-            c.set_sliding_sync_proxy(builder.sliding_sync_proxy);
-            Ok(Arc::new(c))
-        })
+        RUNTIME.block_on(async move { Ok(Arc::new(Client::new(inner_builder.build().await?))) })
     }
 }
 
@@ -147,7 +135,6 @@ impl Default for ClientBuilder {
             server_versions: None,
             passphrase: Zeroizing::new(None),
             user_agent: None,
-            sliding_sync_proxy: None,
             inner: MatrixClient::builder(),
         }
     }
diff --git a/bindings/matrix-sdk-ffi/src/sliding_sync.rs b/bindings/matrix-sdk-ffi/src/sliding_sync.rs
index 9a6e518ab..26a84399d 100644
--- a/bindings/matrix-sdk-ffi/src/sliding_sync.rs
+++ b/bindings/matrix-sdk-ffi/src/sliding_sync.rs
@@ -20,7 +20,6 @@ use matrix_sdk::{
 };
 use matrix_sdk_ui::timeline::SlidingSyncRoomExt;
 use tracing::{error, warn};
-use url::Url;
 
 use crate::{
     error::ClientError, helpers::unwrap_or_clone_arc, room::TimelineLock, Client,
@@ -867,15 +866,13 @@ impl Client {
     /// Note: the identifier must be less than 16 chars long.
     pub fn sliding_sync(&self, id: String) -> Result<Arc<SlidingSyncBuilder>, ClientError> {
         let mut inner = self.inner.sliding_sync(id)?;
-        if let Some(sliding_sync_proxy) = self
-            .sliding_sync_proxy
-            .read()
-            .unwrap()
-            .clone()
-            .and_then(|p| Url::parse(p.as_str()).ok())
+
+        if let Some(sliding_sync_proxy) =
+            RUNTIME.block_on(async { self.inner.sliding_sync_proxy().await })
         {
             inner = inner.sliding_sync_proxy(sliding_sync_proxy);
         }
+
         Ok(Arc::new(SlidingSyncBuilder { inner, client: self.clone() }))
     }
 }